Motivational Interviewing (MI) is the only behavioral intervention to date shown to be effective to improve self- management for youth living with HIV. Implementation science is the scientific study of methods to promote the uptake of research findings and evidence-based practice (EBP) to improve the quality and effectiveness of behavior change approaches such as MI in health care settings. A primary challenge of scaling up EBPs is to balance flexibility (adaptation to context) and fidelity (provider adherence and competence). The goal of this proposal is to test a multi-faceted Tailored MI Implementation intervention (?TMI?) based on the dynamic adaptation process to scale up an EBP in multidisciplinary adolescent HIV care settings while balancing flexibility and fidelity. The dynamic adaptation process guides tailoring of MI implementation through a series of phases: exploration, preparation, implementation, and sustainment. The proposed project is a hybrid implementation-effectiveness (Type 3) trial. We will test the effect of TMI on fidelity to the EBP, and secondarily on HIV care cascade-related outcomes, using a dynamic wait-listed design with 165 providers nested within 10 ATN4 HIV sites. With this design, the clinics will be randomly assigned in 5 clusters to receive TMI. For each randomization, 2 clinics receive TMI and the others remain in the wait-list condition. This will continue until the 5th cluster has been randomized to TMI. After one year of TMI?s external facilitation, a second randomization will compare internal facilitator monitoring and coaching plus the encouragement of Communities of Practice versus Communities of Practice alone. Fidelity will be assessed on a quarterly basis through the 24 months of intervention and an additional 6 months of follow-up. We will nest our qualitative method (in-depth interviews) within the quantitative study to provide a deeper understanding of the implementation context and understand why or why not MI is integrated with fidelity across the 150 providers. Providers and key stakeholders will complete qualitative interviews and brief assessments at baseline, after one year of TMI (first randomization), and after 1 year of follow-up (second randomization). We hypothesize that MI competency ratings will be higher among providers during the TMI phase compared to the treatment as usual phase. We also expect that successful implementation will be associated with improved cascade-related outcomes, namely undetectable viral load and greater number of clinic visits among youth living with HIV as well as increased numbers of youth tested and linked to care.